What is a Johnson counter and its unique shifting pattern?
1 Answer
A Johnson counter, also known as a twisted ring counter, is a type of digital sequential circuit used for counting or generating a repeating sequence of binary numbers. It is a modification of the ring counter, where a single '1' bit circulates through a sequence of flip-flops, resulting in a unique shifting pattern.
The Johnson counter has a distinctive shifting pattern that is characterized by its balanced and symmetrical nature. It goes through a series of states, with each state having only one bit set to '1,' and all other bits set to '0.' The '1' bit circulates through the counter in a circular manner, creating a repetitive pattern.
For example, let's consider a 4-bit Johnson counter. It would go through the following states in sequence:
State 1: 0001
State 2: 0010
State 3: 0100
State 4: 1000
State 5: 0100 (repeats state 3)
State 6: 0010 (repeats state 2)
State 7: 0001 (repeats state 1)
As you can see, the Johnson counter follows a unique pattern, where the '1' bit shifts to the right in the first half of the counting sequence and then shifts back to the left in the second half of the sequence. This symmetric shifting pattern distinguishes the Johnson counter from other types of counters like the binary counter or the ring counter. The sequence continuously repeats, creating an oscillating and self-correcting behavior.
Johnson counters find applications in various areas such as control systems, frequency division, and pattern generation, where the unique shifting pattern can be beneficial for certain tasks and requirements.
The Johnson counter has a distinctive shifting pattern that is characterized by its balanced and symmetrical nature. It goes through a series of states, with each state having only one bit set to '1,' and all other bits set to '0.' The '1' bit circulates through the counter in a circular manner, creating a repetitive pattern.
For example, let's consider a 4-bit Johnson counter. It would go through the following states in sequence:
State 1: 0001
State 2: 0010
State 3: 0100
State 4: 1000
State 5: 0100 (repeats state 3)
State 6: 0010 (repeats state 2)
State 7: 0001 (repeats state 1)
As you can see, the Johnson counter follows a unique pattern, where the '1' bit shifts to the right in the first half of the counting sequence and then shifts back to the left in the second half of the sequence. This symmetric shifting pattern distinguishes the Johnson counter from other types of counters like the binary counter or the ring counter. The sequence continuously repeats, creating an oscillating and self-correcting behavior.
Johnson counters find applications in various areas such as control systems, frequency division, and pattern generation, where the unique shifting pattern can be beneficial for certain tasks and requirements.